1. The package of the driving chip should be conducive to the rapid heat dissipation of the driving chip die. For example, the die is directly bound to the copper plate, and a pin is directly extended to the package, so that it can be directly welded to the copper foil of the PCB board to conduct heat quickly (Fig. 1). For example, on a similar 4x4mm silicon die, if the current is 300-1000ma for a long time, there must be power consumption and heating, and the physical heat dissipation layout of the chip itself is also very important.
2. The output current of the driver chip must be stable and stable, so that the LED light source can be stable and luminous, and the brightness will not shine; if the same batch of driver chips are used under the same conditions, the output current size should be as common as possible, that is, the dispersion should be small, so that it can be useful and orderly produced in a large number of automatic production lines; the driver chips with certain discrete output current must be selected Before the factory or the production line is put into production, the resistance value of the current setting resistance (RS) on the PCB board shall be adjusted so that the brightness of the LED lamp constant current driving board to the same LED light source is the same, and the commonness of the end products is insisted.
3. The nominal output current demand of the driver chip is greater than 1.2-1.5a. As the LED light source for lighting, the nominal operating current of 1W LED light source is 350mA, and that of 3W power LED light source is 700mA. Therefore, the driving IC selected for LED floodlight must have enough current output, and the driving IC must work at full load when planning commodities Output of 70-90% of the best operating area. The driving IC with full negative output current has poor heat dissipation, simple fatigue and early failure.